THE heartbroken family of a Lithuanian woman who died from head injuries she sustained after falling from a car at speed are planning to bring her remains home.

Zanna Alem (35), described by friends as a "devoted" mother, was found unconscious in a pool of blood at the Couse Bridge roundabout on the outskirts of Waterford city after midnight on Sunday.

Ms Alem, who had four school-going children, had moved to Ireland around five years ago.

Waterford priest Fr Gerry Chesnutt said local residents were saddened by the death, which was particularly "tragic" for the children.

"The children would have been known as they all go to school locally," he said.

It's understood that Ms Alem's family are making plans for her remains to be repatriated -- and her children may yet have to make the heartbreaking journey home to Lithuania.

"We believe the children will go back to Lithuania with their mother's ashes but those arrangements have not been finalised yet," a source close to the family said.

A 29-year-old man was arrested at the scene where Ms Alem was found unconscious. However, gardai are now satisfied he has no case to answer and that the incident was a tragic accident.

Ms Alem was rushed to Waterford Regional Hospital on Sunday, but died from her injuries. A post mortem revealed the cause of death was head injuries consistent with falling from a car. There was no evidence of assault.

Gardai are continuing to ask witnesses if they spotted any activity in the vicinity on Sunday night to call them on the garda confidential Line -- 1800 666 111 -- or to contact any garda station.